The Associated Press reports that Maj. Nidal Hasan’s attorneys said he wanted to plead guilty. He’s barred, however, by Army rules. Military judges can’t take guilty pleas from defendants who face the death penalty, AP says. So attorneys tried to get the judge to accept a guilty plea for 13 counts of unpremeditated murder — to no avail, AP reports.

Col. Tara Osborn said he can’t plead guilty to anything — premeditated or unpremeditated — because that “would be the functional equivalent of pleading guilty to a capital offense,” she said, as quoted by AP.